Unix timestamp converter

What a Unix timestamp is

Unix time counts the seconds since 00:00:00 UTC on 1 January 1970, the "epoch". It is how most databases, logs, APIs, JWTs and file systems store moments in time, because a single number is easy to compare and has no time zone. JavaScript and many APIs use milliseconds instead (13 digits today), and some systems use microseconds (16 digits). This converter tells them apart by size.

Unix time ignores leap seconds: every day is exactly 86,400 seconds, which keeps arithmetic simple.

Worked example

1700000000 is 1,700,000,000 seconds after the epoch: 2023-11-14 22:13:20 UTC, which was 19:13:20 in São Paulo (UTC−3) and 14:13:20 in Los Angeles (UTC−8). The same instant in milliseconds is 1700000000000. Going the other way, 2024-02-29T12:00:00-03:00 gives 1709218800.

The year 2038

Systems that store Unix time in a signed 32-bit integer overflow at 03:14:07 UTC on 19 January 2038 (2,147,483,647 seconds). Modern systems use 64 bits, which lasts for billions of years.

Numbers are read as seconds, milliseconds or microseconds depending on their size, and dates must follow ISO 8601 (2024-02-29, 2024-02-29T12:00:00Z, or with an offset such as -03:00); a date without an offset is treated as UTC. The page then shows the instant as Unix seconds and milliseconds, ISO 8601, a full date in UTC and in your browser's time zone, how long ago or ahead it is, its ISO week and its day of the year. Relative and local times refresh with your clock when the page opens. Everything runs in this tab.